The present invention relates generally to dental impression trays, and more particularly to improved dental impression trays for more evenly and efficiently flooding impression material into the tray and around teeth positioned in the tray.
In the fields of dentistry and orthodontics, a wide variety of procedures and techniques require fabricating a model of a patient's teeth. Modeling teeth often requires making accurate castings of a patient's teeth, tooth surfaces, gingival and other fine details of the patient's dentition. Traditional dental castings are made by loading a dental impression tray or shell with a liquid dental impression material, which is generally a viscous and quick setting material that must be quickly applied to the patient's teeth soon after mixing. The tray loaded with impression material is then inserted into a patient's mouth, and the patient closes their mouth in order to hold the tray in position until the impression material has sufficiently solidified. After the material has solidified sufficiently, the tray and impression material are removed, with the solidified material containing an impression of the dental surfaces of the patient.
One problem with existing impression trays lies in the need to load it with impression material and then seat it in the patient's mouth. Loading the tray typically includes layering a thick bead of impression material into a teeth receiving cavity of the tray, e.g., by extruding material from a cartridge gun into the tray cavity. This loading process often results in the encapsulation of air bubbles/pockets if the beads are not correctly extruded, which when applied onto the patient, will produce an inaccurate impression with missing anatomy. Additionally, accurately seating a fully loaded impression tray onto the teeth is difficult and can include misalignment during or after insertion. If the tray is improperly placed or is accidentally shifted during the setting time, the resulting impression will be distorted. Further, as a fully loaded tray has to be applied with a substantial (and uncomfortable) amount of force, such force may displace the impression material out of the tray to create a shallow model and show through as the target anatomy enters the confines of the interior tray cavity.
Recent advances in dentistry and orthodontics has increased the value and need for obtaining accurate, higher quality impressions of patients' teeth. In the field of orthodontics, for example, both traditional orthodontics as well as alternatives to conventional orthodontic treatment with traditional affixed appliances often make use of impressions of a patient's teeth, and as technology progresses higher quality impressions are becoming even more desired. For example, systems including a series of preformed aligners have become commercially available from Align Technology, Inc., Santa Clara, Calif., under the tradename Invisalign® System. The Invisalign® System includes designing and/or fabricating multiple aligners to be sequentially worn by the patient in order to reposition the teeth over time. Often, designing and planning a customized treatment for a patient, as well as administration and monitoring of the treatment itself, makes use of quality impressions, for example, computer-based 3-dimensional planning/design tools, such as ClinCheck® from Align Technology, Inc. However, inconsistent production of suitable quality impressions using current techniques can decrease the effectiveness or efficiency of many of the wide variety of techniques that make use of dental impressions.
As such, there is an increasing need for high quality dental impressions for the wide variety of procedures and techniques in dentistry and orthodontics. In turn, improved systems and methods are needed for producing more accurate and refined impressions of a patient's teeth, as well as impressions that can be more consistently and efficiently produced.